Graphene/copper-based composite heat sinks demonstrate broad application prospects in military equipment thermal management, high-power electronic packaging, new energy vehicles, and 5G communications due to their exceptional properties, including high thermal conductivity, adjustable thermal expansion coefficients, high strength, and low density. However, the industrial-scale application of these materials faces critical challenges during the fabrication of complex structural components, such as inhomogeneous dispersion of graphene within the copper matrix and poor interfacial bonding, which severely degrade the comprehensive performance of graphene/copper-based composites. To address these issues, this paper systematically reviews the preparation methods for graphene/copper-based composite heat sinks and critically analyzes their respective advantages and limitations. Furthermore, it synthesizes recent advances in key scientific challenges, including uniform dispersion of graphene, interfacial optimization mechanisms, and molecular dynamics simulations for elucidating structure-property relationships. Finally, the future development directions of graphene/copper-based composite heat sinks in engineering applications are prospected.